Study on Jacket Design for Offshore Platform considering Optimization of Structural Material and Topology

Abstract

Design of jacket structures for fixed offshore platforms is complicated by the need to assess structural safety and up-front cost. While the jacket structure must be conservatively designed to ensure stability from external forces such as wind, wave, current and operating loads during its entire service life, costs must be reduced through structural design improvements. Well designed a jacket structure with optimized structural material and topology contribute to the structural integrity and reliability of an offshore platform. In this paper, the basic geometry of the jacket is determined in accordance with the classification rules and general jacket design process, and the braces are designed through the study of the topology optimization of the jacket structural material. The subsea penetration pile was decided considering the size of the offshore platform, and the inner diameter of the jacket leg was determined so that the condition of the piles installation was satisfied. In addition, member design for the entire panel was performed considering structural safety of each member such as slenderness ratio, hydrostatic collapse, bucking. The environmental and dynamic loads were replaced with equivalent loads and applied to the 2D plane elements, and the jacket structural material was determined by applying the topology optimization method. The jacket brace arrangement was modified to reflect the topology result, and